Longitudinal evidence for increased functional response in frontal cortex for older adults with hippocampal atrophy and memory decline
2018 (Engelska)Ingår i: Cerebral Cortex, ISSN 1047-3211, E-ISSN 1460-2199, Vol. 28, nr 3, s. 936-948Artikel i tidskrift (Refereegranskat) Published
Abstract [en]
The functional organization of the frontal cortex is dynamic. Age-related increases in frontal functional responses have been shown during various cognitive tasks, but the cross-sectional nature of most past studies makes it unclear whether these increases reflect reorganization or stable individual differences. Here, we followed 130 older individuals' cognitive trajectories over 20-25 years with repeated neuropsychological assessments every 5th year, and identified individuals with stable or declining episodic memory. Both groups displayed significant gray matter atrophy over 2 successive magnetic resonance imaging sessions 4 years apart, but the decline group also had a smaller volume of the right hippocampus. Only individuals with declining memory demonstrated increased prefrontal functional responses during memory encoding and retrieval over the 4-year interval. Regions with increased functional recruitment were located outside, or on the borders of core task-related networks, indicating an expansion of these over time. These longitudinal findings offer novel insight into the mechanisms behind age-associated memory loss, and are consistent with a theoretical model in which hippocampus atrophy, past a critical threshold, induces episodic-memory decline and altered prefrontal functional organization.
Ort, förlag, år, upplaga, sidor
Oxford University Press, 2018. Vol. 28, nr 3, s. 936-948
Nyckelord [en]
aging, fMRI, hippocampus, longitudinal study, memory decline, prefrontal cortex
Nationell ämneskategori
Neurovetenskaper Psykologi (exklusive tillämpad psykologi)
Identifikatorer
URN: urn:nbn:se:umu:diva-131270DOI: 10.1093/cercor/bhw418ISI: 000426817600010PubMedID: 28119343Scopus ID: 2-s2.0-85059637194OAI: oai:DiVA.org:umu-131270DiVA, id: diva2:1073359
2017-02-102017-02-102023-03-24Bibliografiskt granskad